CARDAN

From Agepedia

CARDAN, or CAUDANO, Geronimo (Hieronymus Cardanus). This famous philosopher, physician and mathematician was born in 1501, at Pavia, and was educated, from his fourth year, very carefully, in the house of his father, a physician and lawyer in Milan, distinguished for his learning and integrity. In his 20th year, he went to Pavia to complete his studies; and, after two years, he began to explain Euclid. He was, subsequently, professor of mathematics and medicine in Milan. He then returned to Pavia, again visited Milan, taught, for some time, at Bologna, and, meeting with some difficulties there, went to Rome. Here he was received into the medical college, and was allowed a pension by the pope. He declined the invitations of the king of Denmark, on account of the climate and of the religion of that country. The latter reason for his refusal appears strange from a man who was accused of itreligion ; but his biographers differ with regard to his religious opinions. Contradictory passages are cited from his works, which cannot surprise us in one who was lost in cabalistic dreams and paradoxes, and pretended to have a familiar demon (daemon familiaris), from whom he received warnings, &c. All this excited the theologians against him, who attacked his orthodoxy, and even accused him of atheism, but certainly without foundation. The truth is, that Cardan was superstitious, but his chimeras were in opposition to the reigning superstitions of the age. tie believed so implicitly in astrology, that he drew his own horoscope several times, and ascribed the falsehood of his predictions, not to the uncertainty of the art, but to his own ignorance. His two works, De Suhtilitate and De Rerwn Varietate, contain the whole of his natural philosophy and metaphysics, and are curious as an instance of a strange mixture of wisdom and folly. Cardan wrote, also, on medicine. His writings on this subject, amid much trash, contain some sound ideas. His fame as a physician was so great, that the primate of Scotland, who had been sick for 10 years, and had consulted the physicians of the king of France and of the emperor of Germany without success, invited him to Scotland, and was restored to health by his. prescriptions. His highest claims to the gratitude of the learned rest on his mathematical discoveries. Algebra, which, from the time of its origin, had,been cultivated almost exclusively in Italy, excited, at that time, much rivalry" among the mathematicians, who carefully kept their discoveries secret, in order to triumph over each other in their public disputes. Cardan, it is said, was told that Tartalea had discovered the solution of equations of the third degree, and obtained the secret from him by stratagem and under promise of silence, but published the method, in 1545, in his Ars magna, A violent dispute arose, which cannot now be derided with certainty. The honor of giving his name to the invention has remained to him who first made it known, and it is still called the formula of Cardan, It is universally believed that Cardan discovered some new cases, which were not comprehended in the rule of Tartalea: that he discovered the multiplicity of the roots of the higher equations, and, finally, the existence of negative roots, the use of which he did not, however, understand. His tranquillity was disturbed, not only by the attacks of his enemies, but also by his own extravagancies, which are related in his work Be Vita propria, no doubt with much exaggeration. They are exposed with so much frankness, that those who have judged him with indulgence have been obliged to suppose him subject to fits of insanity. He died, probably, in 1576, according to some accounts, by voluntary starvation, that he might not survive the year in which he had predicted that his death would occur. All his works, to the number of more than 50, are contained in the edition of Lyons, 1663, in 10 vols., fol.